Slotting machine



Nov, 14, 31959 T. F. ESERKALN ETAL 9 SLOTTING MACHINE Filed July 11,1946 4 Sheets-Sheet 1 INVENTORS yerkzln Qr/Qy c2? Pmmske W M w NOW 91950 T. F. ESERKALN ETAL. 5 9

SLOTTING MACHINE Filed July 11, 1946 4 Sheets-Sheet 2 Novo 14,. 1950Filed July 11, 1946 T. F. ESERKALN ETTAL SLOTTING MACHINE 4 Sheets-Sheet4 Patented Nov. 14, 1950 SLOTTING MACHINE Theodore F. Eserkaln,Wauwatosa, and Charles A. Parske, Milwaukee, Wis., assignors to Kearney& Trecker Corporation, West Allis, Wis., a corporation of WisconsinApplication July 11, 1946, Serial N0. 682,850

9 Claims. (CI. 9040) This invention relates generally to machine toolsand more particularly to an improved slotting mechanism for a machinetool.

A general object of the invention is to provide an improved machine toolof the reciprocating ram type.

Another object of the invention is to provide an improved slottingattachment which may be mounted on any of various machine tools.

Another object of the invention is to provide an improved controlmechanism for changing the range of movement of a ram in a slottingmechanism, which is adjustable while the ram is reciproeating.

Another object is to provide an improved slotting mechanism having novelselective means to vary the range of ram movement.

According to this invention, an improved machine tool slotting mechanismhas been provided wherein the tool carrying ram may be adjusted foroperation through a predetermined distance, the adjustment being madewhile the ram is reciprocating. The ram is power driven from a motormounted on the machine frame and connected to drive a step pulleytransmission which provides means for varying the rate of ramreciprocation. A crankcase adjustably mounted in the frame carries anoscillatory ram actuating arm so arranged that movement of the crankcaseprovides means for adjusting the range of ram reciprocation withinprescribed limits. Appropriate indicia are provided to indicate therange setting of the ram, while a drive mechanism within the crankcasetransmits power to drive the ram regardless of the position of the casein the frame.

The foregoing and other objects of this invention, which will becomemore fully apparent from the following detailed description of anembodiment thereof, may be achieved by the apparatus herein described byway of example in connection with the illustration of its structuralcomponents in the accompanying drawing, in which:

7 Figure 1 is a front elevational view of a slotting attachment,incorporating the invention herein disclosed, mounted on a machine toolfor operation on a workpiece;

Fig. 2 is a vertical sectional View ofthe slotting attachment shown in-Fig. 1-, showing the drive mechanism adjusted to provide maximum ramtravel;

Fig. 3 is a view generally similar to Fig. 2, showing the drivemechanism adjusted to provide a shorter ram travel;

Fig. 4 is a detailed vertical sectional view of drive mechanismcontained within the adjustably positioned crankcase, showing the powerdrive train;

Fig. 5 is a view in vertical transverse section on the plane of the line55 in Fig. 1 of the slotting attachment'mounted on a machine toolshowing the ram and crankcase mounting in greater detail; and,

Fig. 6 is a fragmentary horizontal sectional view, taken on the plane oflines 66 in Figs. 2 and 5, showing the drive train from the drivenpulley to the ram within the attachment frame.

The particular structure illustrated in the.

drawing as constituting mechanism disclosing the invention, is aslotting attachment adapted for mounting on a machine tool, although itis to be understood that the novel features thereof may be incorporatedin other machine tools of the reciprocating ram type with equaladvantage.

Referring more specifically to the drawings, the slotting attachmentembodying the invention comprises a frame 9, mounted for angularpositioning on an upright column 10 of a horizontal spindle, knee typemilling machine. A ram ll, reciprocally mounted in the attachment frame9 serves to support a cutting tool l2 on its lower end in a manner toeffect a slotting operation upon a workpiece l3, clamped on a worksupporting table I4 adjustably carried by the column [0 of the machinetool, as shown in Fig. 1. Power for driving the ram 1 I is derived froma motor l5 adjustably carried on the top of the attachment frame 9. Therate of ram movement and, consequently, of tool reciprocation, iscontrolled by adjusting a step pulley transmission 19 in well knownmanner. According to this invention, the range of reciprocation of theram l I may be precisely controlled by adjusting the position of acrankcase or gear case 20 movably mounted within the frame 9. Selectivepositioning of the crankcase 20 serves to vary the ram stroke, bychanging the efiective operating length of an oscillating actuating arm2| mounted upon the crankcase and slidably engaging a swivel block 22journalled in the side of the ram.

The shape of a slot 23 cut in the workpiece I3 is determined in part bythe contour of the cutting edge of the tool I 2, while the depth of theslot may be set by selectively positioning the various machine toolelements, including the table I, in a manner well known to those skilledin machine tool operation. In addition, when a particular slot has beencompleted, the workpiece may be repositioned relative to the cutter topermit succeeding slots to be cut. When a slotting operation is beingperformed on an arcuate element either on the periphery of or within anopening in a workpiece, the workpiece may be mounted upon a rotary table(not shown) in a manner to permit accurate angular positioning thereof.

The motor 5 is hingedly mounted for adjustment on the attachment frame 9by means of a pin 26, as shown in Fig. 5. A step pulley 21, constitutingthe driving unit of th pulley transmission l9, as shown in Fig. 2, iskeyed directly to the armature shaft extending from the motor l5. Acomplementary driven step pulley 28 of the transmission [9 is rotatablyjournalled in the attachment frame 8. Both pulleys are housed within aninclosed compartment 29 in the frame, in such a manner that therespective pulley grooves are parallelly mated to receive a V-belt 30.For servicing and adjusting the pulley transmission mechanism, access tothe compartment may be had through an opening closed by a re movablebolted cover 3 i. The tension of the belt 39 1s readily varied bymanipulating a knob 32 pinned to the upper end of an adjusting screw 33.As shown, the screw 33 is threaded in a lug 34 integrally formed withand extending from the motor frame, with the lower end of the screwabutting against the attachment frame and supporting the motor l5. Whenthe knob and screw are rotated, the motor i5 is raised or lowered totension or release the belt on the pulleys. By selectively positioningthe belt 30 in the various combinations of grooves as shown in Figs. 2and 6, a splined shaft 35, that is slidably received by internal splinesin the pulley 28 may be driven at any one of five speeds. Access to thepulley transmission IQ, for changing the position of the belt in thevarious grooves of the pulleys 2i and 28, is obtained through an opening35 provided in the frame 8, as shown in Fig. 6.

The range of ram reciprocation is selectively changed by positioning thecrankcase 20 within the attachment frame 9, in a manner to change theeffective length of the oscillating actuating arm 2| in acting upon theswivel block 22. As shown in Figs. 2 and 5, the crankcase 20 is providedwith a dovetailed portion 3? which is slidably received for transversemovement in a correspondingly shaped groove 33 machined in ahorizontally disposed guide block 39 attached to the inside of coverplate 40 constituting the front of the frame 9. The crankcase assembly25, actuating arm 2!, swivel block 22 and ram H are assembled as a uniton the cover plate 40, before the cover is bolted to the frame.

The crankcase assembly 20 is adjustably positioned by selectivelyrotating a handwheel 43, shown in Figs. 1, 2, and 3, mounted on theextending end of a screw shaft 4:1 journalled in the frame 9 in a planeparallel to the plane of crankcase movement. A bore in the crankcase isthreaded to receive the threads of the screw shaft 44, in a manner toefiect movement of the crankcase 2!] whenever the handwheel 43 isrotated. Appropriate indicia 46, marked on the crankcase structure, whenread against a zero mark 41, through a window in the cover plate 4|], asshown in Fig. 1, permits the operator to readily ascertain the settingof the crankcase and, consequently, the range setting of thetool-retaining ram Thus, the machine operator can readily adjust thelength of ram stroke to meet the requirements of a particular slottingoperation.

When the handwheel is rotated to adjust the position of the crankcaseassembly 20, the oscillating actuating arm 2| is slidably positionedwithin the swivel block 22 to provide for transmitting a desiredeffective movement to the ram When so adjusted to a desired operatingrange, the ram and the tool l2, carried thereby, will be reciprocatedprecisely within the prescribed range. With this structure, the operatorcan readily adjust the length of ram stroke while the ram is performinga slotting operation upon a workpiece.

In order to provide a power drive to effect reciprocation of the ram Ifor any desired adj ustment of the crankcase assembly 20, a linkagemechanism is contained therein, as shown in detail in Figs. 4 and 6. Thesplined driving shaft 35 is supported in the crankcase 20 on a doubleball bearing 5|. A pinion 52, integrally formed on the inner end of thesplined shaft 35, meshes with a ring gear 53 carried on a crankshaft 54,that is journalled in the respective side walls of the crankcase 2|] inbearings 55 and 56. Thus, the crankshaft 54 may be rotatably driventhrough interaction of the ring gear and pinion 52 and 53 at a speedrate determined by the setting of the belt 30 in the step pulleytransmission H].

A connecting rod 51, journalled on the throw of the crankshaft 54, isoperatively connected with the extending end of a forked arm 58 by meansof a wrist pin 59, as shown in Fig. 4. The arm 58 is keyed to a rockshaft 60, journalled in and extending from the crankcase 20 with itsaxis parallel to that of the crankshaft 54. When the crankshaft 54 isrotatably driven, the connecting rod 5'! will cause the arm 58 tooscillate through a prescribed distance for each rotation of thecrankshaft 54 and, consequently, the shaft 60 will be partially rotatedor oscillated through the same angular displacement. An offset carrierarm 6| is keyed to the forwardly extending end of the rockshaft BB andserves to support the actuating Thus, when the shaft 6|! is oscillatedby the connecting rod 51, the carrier arm 6| will be correspondinglyoscillated or reciprocated along a fixed arcuate path.

As shown in Figs. 2, 5, and 6, the actuating arm 2| presents acylindrical surface that slidably engages the interior of a bore 62 inthe swivel block 22. Since the swivel block 22 is rotatably journalledon a bearing 63 mounted in the side of the ram I, as shown in Figs. 5and 6, the block is free to swivel about its axis as well as slide uponthe arm 2| and any oscillatory movement of the arm will be translatedinto endwise movement of the ram I I that is slidably retained within aram track 64 in the cover plate 40. Selective adjustment of thecrankcase assembly, as aforedescribed, serves to change the effectivelength or setting of the actuating arm in the swivel block 22. Thus, asviewed in Figs. 2 and 6, when the crankcase assembly 20 is positioned inthe extreme left hand position within the frame 9, the actuating arm 2|will operate at its maximum effective length and serves to effect themaximum travel of the ram within the ram track 54.

Any adjustment of the crankcase assembly 20 rightwardly as seen in thedrawings, will serve to reposition the actuating arm 2| in the swivelblock 22 and, consequently, will reduce its effective length and therange of ram travel. For example, as shown in Fig. 3, with the crankcaseassembly 20 adjusted to effect a reduction in the range of ram travel,the arm 2| will have been moved rightwardly in the swivel block 22 a setdistance. With this setting, the distance between the center of therockshaft 60 and the pivot center of the swivel block 22 is reduced sothat the oscillatory action of the arm 2| will effect a proportionatelyshorter ram travel. When the two centers coincide, the arm 2|.will bepositioned for zero ram travel. A dotted line showing in Fig. 3indicates the lowest position which the ram and tool reaches for theparticular range setting shown, the actual distance of travel beingindicated by an arrow 65 as compared with the maximum distance of travelindicated by an arrow 66 in Fig. 2. This distance of ram travel will beindicated to the machine operator by the previously described rangeindicia 46 and each ram stroke will be of identical length, thearrangement providing infinitely variable range adjustment within thefixed limits of crankcase adjustment. I

In order that a slotting operation may be performed on a workpiecehaving an inclined surface, a swivel mounting is provided for theattachment. The frame 9 is provided with a rearwardly extending flange10, as shown in Figs. 5 and 6, having a circular engaging surface H,which is disposed to concentrically engage a similar surface on abacking plate 12. The plate is in this instance supported on a pair ofextending overarms l3, slidably mounted in the machine tool column ID.The plate is rigidly clamped to the column by means of a gib 14, in amanner well known to the machine tool art. The attachment frame Sisrigidly secured to the plate 12 by means of four T-bolts and nuts 15,evenly spaced about the periphery of the flange 10. The T-bolts ride ina circular T-slot [6 machined in the supporting plate 12. When theslotting attachment is to be set to cut slots at a desired'angle, themachine operator-need only loosen the four nuts andswivel the entireunit to the desired position and reclamp the nuts to rigidly hold theslotting attachment in a selected angular position. Indicia 11 marked onthe peripheral edge of the flange 10, when read against a zero mark 78on the plate 12, as shown in Fig. 5, enables the o erator to readilyascertain the exact angular setting of the attachment.

From the foregoing detailed description of the illustrative structuresset forth herein to exemplify the present invention, it will be apparentthat there has been provided an improved machine tool of thereciprocating ram type that is especially adapted for cutting slots inworkpieces under various conditions of operation.

Although the exemplary embodiment of the invention has been described inconsiderable detail in order to fully disclose a practical workingapparatus incorporating the invention, it is to be understood that theparticular structure shown and described is illustrative only and thatthe various characteristics of the invention may be incorporated inother structural forms without departing from the spirit and scope ofthe invention as defined in the subjoined claims.

The principles of the invention having now been fully explained inconnection with the foregoing description of embodying structure, wehereby claim as our invention:

1. In a machine tool of the reciprocatory ram type, a frame, a ramslidably mounted in said frame for reciprocating movement along its1ongitudinal axis, power driven actuating mechanism slidably mounted insaid frame for adjusting movement along a path transverse to thelongitudinal axis of said ram, an oscillatory arm carried by and drivenby said actuating mechanism for oscillatory movement in the direction of6-: movement of said ram, and linkageslidably engaging said arm andoperatively interconnecting said arm and said ram, the arrangement beingsuch that movement of said actuating mechanism relative to said ram axiscauses said arm to slide in said linkage andchanges the effective lengthof said oscillatory arm thereby affording adjustment of the length ofthe stroke of movement imparted to said ram.

2. In a machine tool of the reciprocatory ram type, a frame, a ramslidably mounted in said frame for longitudinal reciprocating movement,

power driven actuating mechanism slidablyl mounted in said frame foradjusting movement transversely of the axis of reciprocatory move-.

ment of said ram, an oscillatory actuating member operatively connectedto and carried by said slidably mounted actuating mechanism and slidablyconnected with said ram to transmit movement to said ram in manner toreciprocate it, means to adjust the position of said actuating mechanismtransversely of said ram to change the slidable connection between saidoscillatory actuating member and said ram for regulating the action ofsaid oscillatory actuating member, upon said ram to vary the length ofits stroke, and indicating means responsive to movement of saidactuating mechanism in said frame and operative to indicate the ramstroke.

3. In a machine tool of the reciprocatoryram type, a frame, a ramslidably mounted in said frame for reciprocating movement along itslongitudinal axis, a power driven actuating shaft rotatably mounted insaid frame, oscillatory mechanism slidably mounted in said frameforadjusting movement in direction transverse to the longitudinal axis ofsaid ram and slidably connected to said power driven shaft for actuationthereby in any position, and motion transmitting linkage including anoscillatory arm operatively connected to be oscillated by said actuatingmechanism and slidably connected to said ram, the arrangement being suchthat the effective length of said arm may be varied by adjusting theposition of said actuating mechanism relative to said ram axis forsliding said arm in its connection with said ram to thereby vary thelength of the stroke of said ram.

4. In a slotting mechanism, a frame, a motor adjustably mounted on saidframe, adjusting means to effect selective adjustment of said motor, adriven shaft journalled in said frame, a

'flxed-step pulley transmission interconnecting said motor and saiddriven shaft to provide a plurality of speed rates therefor, a crankcaseadjustably mounted in said frame, a crankshaft journalled in saidcrankcase, interconnecting driving mechanism to transmit power from saiddriven shaft to said crankshaft regardless of the position of saidcrankcase, a connecting rod disposed for operation on said crankshaft,an arm assembly journalled in said crankcase and reciprocally driven bysaid connecting rod, a tool i retaining ram slidably mounted in saidframe,

mechanism and extending from said case, an actuating arm fixedly carriedby said shaft, a ram slidably mounted in said frame, a swivel-jointedconnector mounted on said ram and carrying said arm, and a selectivelyoperable adjusting mechanism disposed to position said transmission casein said frame, whereby the effective movement of said arm in saidconnector may be varied to change the length of ram stroke while saidram is reciprocating.

6. In a machine tool slotting mechanism, a frame, a carrier mechanismadjustably mounted in said frame, a power source, a transmission drivenby said power source, a coupling journalled in said frame to connectsaid transmission and said carrier mechanism, an adjusting mechanismoperative to selectively adjust the position of said carrier mechanismin said frame, a tool retaining ram slidably mounted for reciprocationin said frame, a swivel block journalled in said ram, and an actuatingarm connected to and extending from said carrier mechanism with said armslidably engaging said swivel block, whereby the manipulation of saidcarrier adjusting mechanism serves to change the effective position ofsaid arm in said block and effect a corresponding change in the range ofram movement.

7. A slotting mechanism for a machine tool comprising a frame mountableon a machine tool, a tool retaining ram reciprocably carried by saidframe, a swivel block journalled in said ram, a power source, acrankcase adjustably carried in said frame, a crankshaft journalled insaid crankcase and rotatively driven by said power source, a secondaryshaft mounted in said frame,

a connecting linkage between said crankshaft and said secondary shaft toeffect rotative reciprocation of said secondary shaft, and an armfixedly mounted on said secondary shaft and slidably mounted in said ramswivel block, whereby the range of ram reciprocation may be varied byselectively positioning said crankcase to vary the effective setting ofsaid arm in said ram block.

8. A slotting attachment for a machine tool comprising a frame, areciprocal ram slidably mounted in said frame, a power source mounted onsaid frame, a crankcase mounted for slidable adjustment in said frame, acrankshaft rotatably journalled in said crankcase, a variable speedtransmission driven from said power source and connected to drive saidcrankshaft in any adjusted position of said crankcase, a bellcrankoperably journalled in said crankcase, a connecting rod operablyattached to said crankshaft and to said bellcrank, a swivel blockjournalled in said ram, and a pivot arm fixedly carried by saidbellcrank and slidably disposed in said block, whereby said ram isreciprocally driven from said power source to perform a slottingoperation.

9. In a slotting attachment for a milling machine having a work holdingtable, a frame disposed to be attached to a milling machine incooperating relationship with its work holding table, said frameconstituting a housing for driving mechanism and presenting an openingat one side, a cover plate disposed to close said opening, said platebeing removably secured to said frame, a slotting tool carrying ramslidably mounted on said cover plate in manner to extend therefromtoward the work holding table, a ram driving transmission mechanismslidably mounted on said cover plate for movement transversely of thesliding movement of said ram, a pendulum arm carried by saidtransmission mechanism and arranged to be oscillated thereby, andlinkage slidably connected with said pendulum arm and operativelyconnecting it with said ram for reciprocating said ram, the arrangementbeing such that movement of said transmission mechanism along said coverplate relative to said ram changes the effective length of said pendulumarm in manner to adjust the length of the stroke of said ram, saidtransmission mechanism and said ram being removable from said frame withsaid cover plate as a unit.

THEODORE F. ESERKALN. CHARLES A. PARSKE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 116,394 Banks June 27, 1871596,528 Morton Jan. 4, 1898 678,172 Grist July 9, 1901 678,341 HolmbergJuly 9, 1901 699,551 McKinney May 6, 1902 790,259 Mills May 16, 1905791,732 Taylor June 6, 1905

